{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-77528", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-08-20T20:23:02.508Z", "datePublished": "2026-09-18T19:42:18.767Z", "dateUpdated": "2026-09-18T19:42:18.767Z"}, "containers": {"cna": {"title": "Autobahn Python permessage-deflate bypasses maxMessagePayloadSize after inflation", "problemTypes": [{"descriptions": [{"cweId": "CWE-409", "lang": "en", "description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-770", "lang": "en", "description": "CWE-770: Allocation of Resources Without Limits or Throttling", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}}], "references": [{"name": "https://github.com/crossbario/autobahn-python/security/advisories/GHSA-hxp9-w8x3-p566", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/crossbario/autobahn-python/security/advisories/GHSA-hxp9-w8x3-p566"}, {"name": "https://github.com/crossbario/autobahn-python/pull/1916", "tags": ["x_refsource_MISC"], "url": "https://github.com/crossbario/autobahn-python/pull/1916"}, {"name": "https://github.com/crossbario/autobahn-python/commit/77d323a30b09b1828ad8be2ce6344e056970e613", "tags": ["x_refsource_MISC"], "url": "https://github.com/crossbario/autobahn-python/commit/77d323a30b09b1828ad8be2ce6344e056970e613"}, {"name": "https://github.com/crossbario/autobahn-python/releases/tag/v26_7_1", "tags": ["x_refsource_MISC"], "url": "https://github.com/crossbario/autobahn-python/releases/tag/v26_7_1"}], "affected": [{"vendor": "crossbario", "product": "autobahn-python", "versions": [{"version": "< 26.7.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-18T19:42:18.767Z"}, "descriptions": [{"lang": "en", "value": "Autobahn Python is a WebSocket and WAMP implementation for Python that supports Twisted and asyncio. Prior to 26.7.1, WebSocket endpoints that accept permessage-deflate and rely on maxMessagePayloadSize enforce that limit against the compressed frame length before inflation but do not recheck the decompressed message size before delivery. A remote unauthenticated client can send a valid compressed frame below the configured wire-size limit that expands beyond the application message limit, causing oversized data to be allocated, joined, validated, and passed to application callbacks. This can create resource-exhaustion pressure, but the advisory does not establish confidentiality or integrity impact. This issue is fixed in version 26.7.1."}], "source": {"advisory": "GHSA-hxp9-w8x3-p566", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "autobahn-python", "vendor": "crossbario", "versions": [{"status": "affected", "version": "< 26.7.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Autobahn Python is a WebSocket and WAMP implementation for Python that supports Twisted and asyncio. Prior to 26.7.1, WebSocket endpoints that accept permessage-deflate and rely on maxMessagePayloadSize enforce that limit against the compressed frame length before inflation but do not recheck the decompressed message size before delivery. A remote unauthenticated client can send a valid compressed frame below the configured wire-size limit that expands beyond the application message limit, causing oversized data to be allocated, joined, validated, and passed to application callbacks. This can create resource-exhaustion pressure, but the advisory does not establish confidentiality or integrity impact. This issue is fixed in version 26.7.1."}], "id": "CVE-2026-77528", "lastModified": "2026-09-18T20:17:22.830", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-09-18T20:17:22.830", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/crossbario/autobahn-python/commit/77d323a30b09b1828ad8be2ce6344e056970e613"}, {"source": "security-advisories@github.com", "url": "https://github.com/crossbario/autobahn-python/pull/1916"}, {"source": "security-advisories@github.com", "url": "https://github.com/crossbario/autobahn-python/releases/tag/v26_7_1"}, {"source": "security-advisories@github.com", "url": "https://github.com/crossbario/autobahn-python/security/advisories/GHSA-hxp9-w8x3-p566"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-409"}, {"lang": "en", "value": "CWE-770"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}